Perioperative molecular effects of faricimab versus aflibercept in proliferative diabetic retinopathy: a randomized comparative study

Abstract To compare perioperative molecular responses and safety of preoperative faricimab versus aflibercept in proliferative diabetic retinopathy (PDR) undergoing pars plana vitrectomy (PPV), and to determine whether dual Ang-2/VEGF-A inhibition induces distinct intraocular molecular remodeling. This prospective, randomized comparative study included forty treatment-naïve PDR patients undergoing PPV and 10 age- and sex-matched cataract controls. Aqueous humor samples were collected from PDR and age- and sex-matched individuals with uncomplicated cataract. For cross-sectional analysis, untreated or baseline pre-injection PDR samples were compared with cataract control samples. Paired pre- and post-treatment aqueous humor samples were obtained from PDR patients scheduled for PPV following intravitreal anti-VEGF treatment, including a faricimab group and an aflibercept group. Post-treatment samples were collected at the start of PPV, 7 days after preoperative intravitreal injection. Thirty-two predefined proteins were quantified using parallel reaction monitoring (PRM)-based targeted proteomics, and four metabolites were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Differentially expressed proteins and metabolites were identified using thresholds of |log2 FC| > 0.3 and P < 0.05. Ocular and systemic adverse events were systematically monitored and recorded. Results No serious ocular or systemic adverse events were observed in either treatment group, and the safety profile of faricimab was comparable to that of aflibercept (P > 0.05). In the faricimab group, pro-fibrotic proteins including IGF-1, CCN2 (also known as CTGF), CCL2, FGF2, and GFAP were significantly downregulated after treatment, whereas the inflammatory factor ICAM-1 and the anti-fibrotic protein GALNS were significantly upregulated. Compared with the aflibercept group, the faricimab group showed significantly higher levels of ICAM-1, GFAP, and GALNS, alongside significantly lower NOS2 levels. Among the four metabolites analyzed, 3-hydroxypropionic acid (3-HPA) was significantly elevated in PDR eyes compared with controls and further increased following faricimab treatment, whereas lactate, an anaerobic glycolysis marker, increased after aflibercept treatment. Principal component analysis (PCA) revealed partial overlap between the two anti-VEGF treatment groups and clear separation from cataract controls. Preoperative intravitreal faricimab administered 7 days before PPV suggests a favorable safety profile in PDR patients. Faricimab significantly suppresses several pro-fibrotic factors in aqueous humor, suggesting a potential benefit in reducing postoperative fibrovascular proliferation. GALNS, ICAM-1, and NOS2 may serve as candidate biomarkers for distinguishing the biological effects of faricimab and aflibercept. The potential role of 3-HPA requires validation in larger cohorts. Clinical trial registration The study protocol adhered to the tenets of the Declaration of Helsinki and was approved by the Institutional Review Boards of Foshan Second People’s Hospital (Approval No. (2024)-0052). Written informed consent was obtained from all participants prior to enrollment. The study was prospectively registered at the Chinese Clinical Trial Registry on April 9th, 2025 (ChiCTR2500100448; PID262770).